Heat exchanger

ABSTRACT

The invention relates to a heat exchanger ( 1 ), especially for motor vehicle air conditioning systems, said heat exchanger comprising at least one header ( 4 ) and a holding element ( 16 ) which is fixed to the header ( 4 ).

The invention relates to a heat exchanger, in particular for motorvehicle air conditioning systems according to the preamble of patentclaim 1.

Heat exchangers are frequently composed essentially of a heat exchangernetwork or tube/rib block and collecting tubes which are arranged onboth sides. The tubes of the heat exchanger network are usually flattubes between which corrugated ribs are arranged in order to increasethe size of the air-side heat exchanging face. The flat tubes areaccommodated by their ends in passages of the collecting tubes. Theseparts of the condenser are first joined together mechanically and thensoldered in an operation in a soldering oven. The parts are oftencomposed of an aluminum alloy and have solder plating on their surface.In addition, many such heat exchangers have connecting tubes, i.e. forexample a coolant inlet tube for the gaseous phase and a coolant outlettube for the liquid phase of a coolant. The connecting tubes areconnected, for example by means of a flange, to the coolant lines of thecoolant circuit of a motor vehicle air conditioning system. Hitherto,after the soldering process the coolant connecting tubes were solderedinto corresponding openings in the collecting tube by hand, i.e. using asoldering flame, and the flange was also not mounted until after thesoldering process, for example attached to a holding element which hasalready been soldered to the collecting tube in the soldering oven. Theproblem with soldering additional parts to the heat exchanger in thesoldering oven is to secure these additional parts so that they retaintheir predetermined position during the soldering process and after thesoldering process the condenser is also dimensionally accurate withrespect to these additional parts. In order to secure such additionalparts it is known to use soldering devices which keep the parts to besoldered in the desired position. After the soldering, the solderingdevice must be removed. Such soldering devices are disadvantageous sincethey require additional mounting time and also consume energy as aresult of their heating up.

The object of the present invention is to improve a heat exchanger ofthe type mentioned at the beginning to the effect that a holding elementcan be simultaneously soldered to the heat exchanger without a solderingdevice or similar resources and is soldered in its intended positionafter the soldering process.

This object is achieved by the features of patent claim 1. According tothe invention, this is done by positively locking engagement securingthe holding element in a way which is sufficient to keep it in positionduring the soldering process. This provides the advantage that theholding element can be soldered to the heat exchanger in one operationwithout a soldering device and similar resources. This savesconsiderable mounting time and reduces the manufacturing costs of theheat exchanger. Advantageous refinements of the invention emerge fromthe subclaims.

According to a first advantageous refinement of the invention, the shapeof the holding element is adapted to the external shape of thecollecting tube. In particular, the holding element is constructed witha C-shaped section, whose rounded shape is adapted to the rounded shapeof the collecting tube and surrounds it. This results in soldering inthe region of the contact face. It is also advantageous if the C-shapedsection is clipped to the collecting tube. This may be done by means ofcorresponding latching or clamping elements on the limbs of the C-shapedsection. The holding element with the C-shaped section is thereforesimply pressed onto the collecting tube from above during the mountingprocess and is then secured after the clipping process.

One advantageous development provides for the collecting tube to beconstructed in two pieces, that is to say from a bottom piece and a lidpiece, which are soldered to one another by means of two longitudinalseams. Since the lid part and the bottom part overlap in the region ofthe longitudinal seams, a shoulder is provided in the region of thelongitudinal edge. The C-shaped section engages with its limbs in thisshoulder or is supported on this shoulder. This further improves thesecuring of the holding element, in particular if clipping takes placeat the same time.

According to a further advantageous configuration of the invention, aflange for securing connecting tubes is attached to the collecting tubeby means of the holding element, in particular by way of a web. Theholding element is preferably constructed in one piece with the flange,with the embodiment as an extruded section being particularlyadvantageous. The holding element therefore does not need to beconnected to the flange after the soldering process, for example byadditional screws or rivets. The flange is thus secured to thecollecting tube by way of the holding element and can be soldered to theheat exchanger. This saves mounting time once more.

According to one advantageous development of the invention, theconnecting tubes are also attached to the flange and to the collectingtube so that these parts can also be soldered tight to the heatexchanger in one operation. This step also shortens the manufacturingtime and reduces the fabrication costs.

According to a further advantageous embodiment of the invention, anextruded flange with holding element which has a concave section with alongitudinal groove is secured to the collecting tube by means of asecuring piece by caulking and clamping. This provides the advantagethat the connecting flange can be soldered to connecting pipes in thesoldering oven without further mounting operations for attaching theflange being necessary after the soldering.

In a further embodiment of the invention, the holding element is in theshape of a plate-shaped web with bent side faces or limbs whose loweredges are adapted to the rounded shape of the collecting tube. As aresult, these bent limbs have a supporting function so that the holdingelement cannot tilt on the collecting tube during the solderingprocesses but is instead fixed. As a result, a securing process iscarried out by means of a positive fit in this embodiment of the holdingelement also.

According to one advantageous development of the invention, the holdingelement has, on its lower edge a lug which is plugged into acorresponding slot in the collecting tube. This provides a furtherimprovement of the securing of the holding element with respect to thecollecting tube since, in this way, a further positive fit is formed. Asa result, this holding element which serves for the subsequentattachment of the tube flange can be soldered in a dimensionallyaccurate fashion to the heat exchanger in the soldering oven.

According to a further advantageous refinement of the invention, theholding element is embodied as an extruded part. This provides theadvantage of a soldering face which is increased in size, i.e. theholding element can be loaded to a greater extent. Furthermore, theadvantage of lower manufacturing costs compared to a pressed holdingelement is obtained.

In a further advantageous refinement of the invention, the holdingelement has a C-shaped section with a central rib, i.e. as it were anE-shaped section. The rib is plugged into a corresponding slot in thecollecting tube and caulked—and in this way the holding element issecured and can be soldered in the soldering oven without furthersecuring means. At the same time, the advantage is obtained of moreaccurate positioning of the holding element by means of a rib and aslot.

In a further refinement of the invention, the holding element has aholding plate which adjoins the outside of the C-shaped section, that isto say is part of the entire extruded section. The holding plate can bebent, curved or else have other shapes which are provided by extrusionwithin the scope of manufacture. In one advantageous refinement of theholding plate it can have attachment bores or cutouts which aremanufactured by further processing, for example by hole punching.

In a further advantageous refinement of the invention, the C-shapedsection forms, on its concave side, a soldering face in which grooveswhich are produced by extrusion are arranged. This provides theadvantage of improved soldering because a better flow of solder is madepossible by the grooves. The solder can thus be distributed uniformlyover the entire soldering face and be soldered there. This providesincreased strength for the entire holding element. This advantage thusalso results from the manufacturing method by extrusion.

According to a further embodiment, the heat exchanger is embodied as acondenser and preferably soldered. Heat exchanger tubes and ribs whichform a tube/rib block are particularly advantageous in this contextbecause of the ease of fabrication.

Exemplary embodiments of the invention are illustrated in the drawingand will be described in more detail below. In the drawing:

FIG. 1 shows a condenser with a flange,

FIG. 2 shows a collecting tube of the condenser,

FIG. 3 shows the flange with a holding element as an elevation,

FIG. 3 a shows the flange in a perspective view,

FIG. 4 shows the collecting tube with mounted flange and connectingtubes,

FIG. 5 shows a second exemplary embodiment of a condenser with a holdingelement,

FIG. 6 shows the holding element according to FIG. 5,

FIG. 6 a shows a view from above of the holding element according toFIG. 6,

FIG. 6 b shows a view from the side of the holding element according toFIG. 6,

FIG. 7 shows a condenser with extruded holding elements in a view fromthe front,

FIG. 7 a shows the condenser according to FIG. 7 in a view from below,

FIG. 7 b shows the condenser according to FIG. 7 in a view from theside,

FIG. 8 shows an extruded holding element,

FIG. 8 a shows the extruded holding element according to FIG. 8 in aview from above,

FIG. 8 b shows the extruded holding element in a view from below,

FIG. 8 c shows the extruded holding element in a perspectiveillustration,

FIG. 9 shows a detail X from FIG. 8,

FIG. 10 shows a further exemplary embodiment of a flange with a holdingelement in an exploded illustration, and

FIG. 11 shows the flange mounted according to FIG. 10.

FIG. 1 shows a condenser 1 with a tube/rib block 2, a lower collectingtube 3 and an upper collecting tube 4. The tube/rib block 2 is composed,as is known, or flat tubes (not illustrated in more detail) andcorrugated ribs which are arranged between them. Two coolant connectingtubes are arranged on the upper collecting tube 4, with the coolantconnecting tubes being specifically a coolant inlet tube 5 and a coolantoutlet tube 6 which open into the collecting tube 4 at one end and areheld in a flange 7 at the other.

FIG. 2 shows the collecting tube 4 of the condenser 1 according to FIG.1 partially in a perspective view. The collecting tube 4 is constructedin two parts, i.e. it is composed of a lid 8 and a bottom 9 which hasslot-shaped passages 10 for holding the flat tubes of the tube/rib block2. The lid and bottom parts 8, 9 which are each constructedapproximately in the form of a half cylinder overlap in the region oftwo longitudinal seams 11, 12 and thus form stepped longitudinal edges13, i.e. shoulders which run in the direction of the longitudinal edges13.

FIG. 3 shows the flange 7 from FIG. 1 as an individual part,specifically as an elevation in the direction of the longitudinal axisof the collecting tube 4. The flange 7 is manufactured as an extrudedsection made of an aluminum extruded alloy and has, at one end, a block14, a web 15 and a holding element 16 which is embodied as a C-shapedsection. The block 14 has two passage openings or connecting openings17, 18 for attaching the connecting tubes 5, 6 and connecting coolantlines (not illustrated). The further bores 19, 20 are used to attach aconnecting flange (not illustrated) for the coolant lines. The C-shapedsection 16 has a concave inner face 16 a whose rounded shape is adaptedto the contour of the lid 8 of the collecting tube 4. In addition, theholding element 16 is defined by two limbs or arms 21, 22 which each endin a flat end region 21 a, 22 a with the concave internal profile 16 abeing stepped with respect to the flat end regions 21 a, 22 a by meansof longitudinal edges 16 b, 16 c.

FIG. 3 a shows the flange 7 according to FIG. 3 in a perspectiveillustration. The figure shows the web 15 which is of flat design andforms the connection between the holding element 16 and block 14 and atthe same time provides a certain degree of elasticity.

FIG. 4 shows the flange 7 with a holding element 16 mounted on the lid 8of the collecting tube 4 together with the coolant connecting tubes 5and 6. The figure shows that the C-shaped section of the holding element16 engages around the lid 8 and is supported with its longitudinal edges16 c, 16 b on the longitudinal edges 13 of the collecting tube 4. Theflat end regions 21 a, 22 a engage around the collecting tube 4 and thebottom 9 and at the same time cause the holding element 16 to be clippedto the collecting tube 4, which is however not illustrated in detail. Atany rate, this engagement of the holding element 16 causes the flange 7to be secured with respect to the collecting tube 4, which is supportedby the simultaneous securing of the coolant connecting tubes 5, 6. Theseare inserted, in a way which is not illustrated in more detail, withtheir ends into corresponding openings in the lid 8 and caulked there.The other ends of the coolant connecting tubes 5, 6 are correspondinglyreceived in the bores 17, 18 of the flange 7. In this respect, theflange 7 is supported and secured to the collecting tube 4 at 3 points,specifically by the coolant connecting tubes 5, 6 on the one hand, andby means of the holding element 16 on the other. The entire condensercan thus be soldered with the parts illustrated in FIG. 4 in oneoperation in a soldering oven (not illustrated). After soldering, thecoolant connecting tubes 5, 6 are soldered tight both to the collectingtube 4 and to the flange 7, and the C-shaped section 16 is soldered inthe region of its contact face 16 a, 16 b, 16 c and 21 a, 22 a to thelid 8 and bottom 9 (both are solder-plated).

FIG. 5 shows a further exemplary embodiment of the invention,specifically a condenser 24 with an upper collecting tube 25 to which aholding element 26 is attached. The holding element 26 is, as isexplained below, secured to the collecting tube 25 before the solderingprocess and then soldered to the entire condenser 24 in the solderingoven. In order to secure the holding element 26 on the collecting tube25, a particular shape is necessary, which is explained below.

FIG. 6 shows the holding element 26 from FIG. 5 as an individual part.FIG. 6 a shows the holding element 26 in a view from above, and FIG. 6 bshows it in a view from the side. The holding element 26 has a planarcentral web part 27 which is embodied as an attachment plate and inwhich two attachment bores 28, 29 are arranged. On both sides of thecentral web part 27, the holding element 26 has limbs 30, 31 which arebent at an approximate right angle to the radius R. As is shown by FIG.6 a, the central web 27 and the two bent limbs 30, 31 produce a type ofU-shaped section. The holding element 26 has a lower edge 27 a in theregion of the central web 27, with the lower edge 27 a being adjoined bywhat is referred to as a lug 32.

FIG. 6 b shows the holding element 26 from the side, with the collectingtube 25 from FIG. 5 being illustrated by dashed lines here. Thecollecting tube 25 has, in its upper region, a slot 25 a whichcorresponds in terms of its dimensions in length and width to those ofthe lug 32. In order to secure the holding element 26, it is thereforefirstly plugged with its lug 32 into the slot 25 a in the collectingtube so that the lower edge 27 a of the web 27 rests on the collectingtube 25. The side limb 30 has an curved lower edge 30 a which is adaptedto the contour 25 b of the collecting tube 25. The same applies to thelateral limb 31 (not shown in FIG. 6 b) which has a corresponding curvedlower edge 31 a. As a result, the two limbs 30, 31 rest with their loweredges over their entire surface on the collecting tube 25 and thusensure that the holding element 26 remains in the position illustratedin FIG. 6 b, i.e., in particular, does not tilt to the side. This isimportant if a flange for connecting coolant lines is attached to thecentral web 27 after the soldering. The holding element 26 is thussufficiently secured and can be soldered to the condenser in thesoldering oven without its position changing significantly.

FIG. 7 shows a soldered condenser 40 for an air conditioning system (notillustrated) of a motor vehicle. The condenser 40 is manufactured fromaluminum materials and is soldered in one operation; and it is composedof a tube/rib block 41 which has flat tubes (not illustrated in moredetail) and corrugated ribs arranged between them. Collecting tubes 42,43 into which the flat tubes open are arranged on both sides of thetube/rib block 41. In each case two holding elements 44, 45, 46, 47,manufactured by extrusion are attached to the two collecting tubes 42,43 by soldering. The holding elements 44 to 47 have, at the ends,cutouts 44 a to 47 a which are used to attach the condenser 40 in thevehicle or to a cooling module (not illustrated). In addition, twoflange connections 48, 49 for letting coolant in and out are attached tothe collecting tube 43.

FIG. 7 a shows the condenser 40 in a view from below, with identicalreference symbols being used for identical parts, i.e. for the holdingelements 44, 47, which have a flat section in this view, and thecollecting tubes 42, 43.

FIG. 7 b shows the condenser 40 in a view from the side in which it isclear that the holding elements 46, 47 engage around the collecting tube43 from above.

FIG. 8 shows, by way of example, the holding element 44 as an individualpart. The other holding elements 45 to 47 are basically of the samedesign. FIG. 8 shows the extruded section of the holding element 44which is composed of an elongated holding plate 44 b and a profiled foot44 c which has an extruded rib 50 and is illustrated as an enlargeddetail X in FIG. 9. The holding plate 44 b has a wall thickness s whichis continuous with the foot 44 c so that the necessary flexural strengthis provided there.

FIG. 8 a shows the extruded holding element 44 in a planar view with awidth b which is a multiple of the wall thickness s. On the side facingaway from the foot 44 c an approximately semicircular recess 44 a isprovided for attachment purposes.

FIG. 8 b shows the extruded holding element 44 from the side, i.e.viewed from the foot 44 c, i.e. the side facing the collecting tube (notillustrated here). The continuous, straight central rib 50 can be seenhere.

FIG. 8 c shows the extruded holding element 44 in a 3-D illustrationwith identical reference numbers being used for identical parts.

FIG. 9 shows, as already mentioned, the foot 44 c of the extrudedholding element 44 as a detail X from FIG. 8. The foot 44 c has anapproximately C-shaped section 51 which corresponds to the contour ofthe collecting tube 42 (not illustrated here)—see FIG. 7 a. In thecentral region of this C-shaped section 51 the rib 50 is arranged as itwere at the apex point of the C-shaped section 51. The C-shaped section51 and the soldering face 51 which is formed by the C-shaped section hasa plurality of grooves 52 which are arranged in parallel with oneanother and which are used to improve the soldering process and thesoldering result. They bring about an improved flow and improveddistribution of the solder during the soldering. The grooves 52 and therib 50 run parallel to one another and in the extrusion direction.

In order to mount the holding element 44 or the holding elements 44 to47, slots (not illustrated) with the dimensions of the rib 50 (see FIG.8 b) are provided in the collecting tubes 42, 43, the ribs beinginserted into said slots and caulked to the collecting tubes. Theholding elements 44 to 47 are thus secured for the subsequent solderingprocess.

FIG. 10 shows, in an exploded illustration, a further exemplaryembodiment of a flange 60 (referred to as a tube connecting flange)which is constructed as an extruded part and has an integrated, i.e.single-piece holding element 61. The flange 60 is of similarconstruction to the flange 7 in FIG. 3 and has two connecting openings60 a, 60 b and two attachment bores 60 c, 60 d. The holding element 61has a concave section 62 and a longitudinal groove 63 at the apex pointof the section 62, i.e. running in the extrusion direction. The flange60 is attached to a collecting tube 65 by means of a securing element64, which collecting tube 65 has an opening 66 for inserting thesecuring element 64. The securing element 64 is of approximatelyT-shaped construction, i.e. with a narrow projection 64 a and a widerpiece 64 b which can be inserted into the groove 63 of the holdingelement 61 in the manner of an adjusting string. The narrow projection64 a is inserted into the opening 66 and caulked there. The holdingelement 61 is then fitted, with the longitudinal groove 63, onto thepiece 64 b so that the concave section 62 surrounds the collecting tube65. The flange 60 is thus secured sufficiently with respect to thecollecting tube 65, i.e. it can now be soldered—to the connecting tubes(not illustrated)—in a soldering oven (not illustrated).

FIG. 11 shows the flange 60 ready mounted with the collecting tube 65.The concave section 62 of the holding element 61 fits snuggly againstthe circumference of the collecting tube 65 and forms a soldering facewith it. The securing element 64 penetrates the collecting tube 65 andis caulked from the inside with its projection 64 a against thecollecting tube 65 so that a positively locking and/or frictionallylocking connection is produced. The piece 64 b which projects out of thecollecting tube 65 is caulked into the longitudinal groove 63 so that aform fit and frictional connection is also produced here. As a result ofthis securing method further soldering aids and subsequent mounting workare superfluous.

1. A heat exchanger (1), in particular for air conditioning systems, in particular for motor vehicles, having at least one collecting tube (4, 5; 65) and a holding element which is attached to a collecting tube (4, 65), characterized in that the holding element (16, 26, 61) can be secured to the collecting tube by positive locking.
 2. The heat exchanger as claimed in claim 1, characterized in that the holding element (16, 26, 61) is adapted to the external shape of the collecting tube (4, 25, 65).
 3. The heat exchanger as claimed in claim 1, characterized in that the holding element is in the shape of a C section (16, 62) which engages around the collecting tube (4, 65).
 4. The heat exchanger as claimed in claim 1, characterized in that the holding element, in particular the C section (16), is clipped to the collecting tube (4).
 5. The heat exchanger as claimed in claim 1, characterized in that the collecting tube (4) is constructed in two pieces and has a lid (8) and a bottom (10) which form offset longitudinal edges (13), and characterized in that the C section (16) has limbs (21, 22) with ends (21 a, 22 a) which are supported on the longitudinal edges (13).
 6. The heat exchanger as claimed in claim 1, characterized in that a flange (7, 60) for securing connecting tubes (5, 6) is attached to the collecting tube by means of the holding element.
 7. The heat exchanger as claimed in claim 6, characterized in that the holding element (16, 61) has a web (15, 61 a) by means of which the holding element (16, 61) is connected to the flange (7, 60).
 8. The heat exchanger as claimed in claim 6, characterized in that the holding element (16, 61) is constructed in one piece with the flange (7, 60), in particular as an extruded part.
 9. The heat exchanger as claimed in claim 6, characterized in that the connecting tubes (5, 6) can be secured at the ends to the collecting tube (4, 65) on the one hand and to the flange (7, 60) on the other, and can in particular be soldered simultaneously to the flange (7, 60) and the heat exchanger (1).
 10. The heat exchanger as claimed in claim 8 characterized in that the holding element (61) can be secured to the collecting tube (65) by means of a securing element (64).
 11. The heat exchanger as claimed in claim 10, characterized in that the holding element (61) has a longitudinal groove (63) for holding the securing element (64 b).
 12. The heat exchanger as claimed in claim 10, characterized in that the collecting tube (65) has an opening (66) for accommodating the securing element (64 a).
 13. The heat exchanger as claimed in claim 11, characterized in that the securing element (64) is caulked to the collecting tube (65) and is clamped to the holding element (61).
 14. The heat exchanger as claimed in claim 1, characterized in that the holding element (26) is in the shape of a web (27) with a straight lower edge (27 a) and with bent limbs (30, 31) with lower edges (30 a, 31 a), and characterized in that the holding element (26) is arranged with its lower edges (27 a, 30 a, 31 a) standing on the collecting tube (25), in which case the lower edges (30 a, 3 a) of the limbs (30, 31) are adapted to the rounded portion (25 b) of the collecting tube (25).
 15. The heat exchanger as claimed in claim 14, characterized in that the web (27) is constructed as a holding plate with attachment openings (28, 29), and the limbs (30, 31) are constructed as supporting elements.
 16. The heat exchanger as claimed in claim 14, characterized in that the holding element (26) has, in particular in the region of the web (27), a lug (32) on its lower side (27 a), said lug (32) being capable of being plugged into a slot (25 a) in the collecting tube (25).
 17. The heat exchanger as claimed in claim 1, characterized in that the holding element (44) is embodied as an extruded part.
 18. The heat exchanger as claimed in claim 17, characterized in that the holding element (44) has a C-shaped section (51), which comprises the collecting tube (42), with a central rib (50) and the collecting tube (42) has a slot for receiving the rib (50).
 19. The heat exchanger as claimed in claim 18, characterized in that the holding element (44) has a holding plate (44 b) which adjoins the C section (44 c).
 20. The heat exchanger as claimed in claim 18, characterized in that the C section (51) forms a soldering face in which grooves (52) which run in the extrusion direction are arranged.
 21. The heat exchanger as claimed in claim 19, characterized in that attachment openings or cutouts (44 a) are arranged in the holding plate (44 b).
 22. The heat exchanger as claimed in claim 17, characterized in that in each case two holding elements (44, 45, 46, 47) are attached to the collecting tubes (42, 43).
 23. The heat exchanger as claimed in claim 1, characterized in that the heat exchanger is, in particular, a soldered capacitor, in which case the heat exchanger has in particular heat exchanger tubes and ribs which are combined to form a tube/rib block. 